Workout Program Help

[Ab4Dayz2000]

So, I've been lifting for the last 6 months after doing a stupid crash diet. I was super skinny fat at the end of my crash diet and wanted to add more muscle mass so I'd look more toned. I started with P90X then changed to BodyBeast. After 6 months of eating a lot everyday and working out as hard as I could everyday I started to see some significant gains on my arms and quads but I'm still fairly skinny fat. I've now deiced that I want to focus on doing less reps and more heavy weight instead of high reps and light weight (To add as much muscle mass as possible). So my question is, what program should I be using to add as much muscle mass as possible

I'm still new to this so any advice is welcome -Thanks!